In the High Court at Rotorua today Justice Ailsa Duffy sentenced the 72-year-old to life in prison for the 1979 murder of Turangi service station attendant Rodney Tahu.
She did not impose a minimum non-parole term, as in 1979 a court was unable to do so. However she said in effect, he would not become eligible for parole until he had served 10 years.
Hallett was found guilty of the murder in May. The case was believed to be New Zealand's oldest cold case to result in arrest.
Justice Duffy told Hallett he had showed "little or no remorse'' for the "cruel, senseless'' murder. She said that attitude had continued throughout the process, with him refusing to discuss his offending with the pre-sentence report writer.
During sentencing one of Tahu's sisters read a victim impact statement on behalf of his siblings.
She said the family had lived for 33 years with the "horror'' of the brutal way in which their beloved and respected husband, father and brother had died and with knowing the man who did it had walked free for 33 years.
"We will never be the same again. The accused [Hallett] changed that for ever.''
Rotorua crown prosecutor Fletcher Pilditch told the judge the murder had been particularly cruel.
"It was nothing short of an execution of the deceased.''
Hallett's lawyer, Paul Mabey, QC, told the judge his client had health issues and the reality was he would "die in prison''.
Mr Mabey argued a life sentence would be "manifestly unjust'' because of the time taken for the prosecution to bring the case and Hallett's personal circumstances.
He referred to Hallett's contribution to the community as a businessman both before and after the murder.
"If we take the 72 years, the single serious blemish was what happened in 1979.''
Justice Duffy said that could not reduce the gravity of what he had done, although she acknowledged imprisonment now was likely to have a harsher effect on Hallett than if he had been jailed as a younger man.
During the trial the jury heard how Hallett pulled into the closed Shell service station in the early hours of August 16, 1979 wanting oil for his car.
Mr Tahu refused to re-open so Hallett called him a "black b******'' then shot three times. The first shot missed, the second one hit Mr Tahu in the shoulder. Hallett then stood over the 32-year-old father-of-two and shot him through the head.
Hallett confessed to his estranged wife hours after the killing and was charged with murder. However, the law of the time prevented people giving evidence against their spouse so he never stood trial.
After the law changed in 2006, the case was re-opened and Hallett was again charged, with his ex-wife the main Crown witness.
